Heavy metal biomonitoring and phytoremediation potentialities of aquatic macrophytes in River Nile

Abstract

The concentrations of Cd, Cu, Pb, and Zn in sediments, water, and different plant organs of six aquatic vascular plant species, Ceratophyllum demersum L. Echinochloa pyramidalis (Lam.) Hitchc. & Chase; Eichhornia crassipes (Mart.) Solms-Laub; Myriophyllum spicatum L.; Phragmites australis (Cav.) Trin. ex Steud; and Typha domingensis (Pers.) Poir. ex Steud, growing naturally in the Nile system (Sohag Governorate), were investigated. The aim was to define which species and which plant organs exhibit the greatest accumulation and evaluate whether these species could be usefully employed in biomonitoring and phytoremediation programs. The recorded metals in water samples were above the standard levels of both US Environmental Protection Agency and Egyptian Environmental Affairs Agency except for Pb. The concentrations of heavy metals in water, sediments, and plants possess the same trend: Zn > Cu > Pb > Cd which reflects the biomonitoring potentialities of the investigated plant species. Generally, the variation of heavy element concentrations in water and sediments in relation to site and season, as assessed by two-way repeated measured ANOVA, was significant (p < 0.05). However, insignificant variations were observed in the concentrations of Pb and Cd in sediments in relation to season and of Cu and Zn in relation to site. Results also showed that the selectivity of the heavy elements for the investigated plants varied significantly (p < 0.05) with species variation. The accumulation capability of the investigated species could be arranged according to this pattern: C. demersum > E. crassipes > M. spicatum > E. pyramidalis > T. domingensis > P. australis. On the basis of the element concentrations, roots of all the studied species contain higher concentrations of Cu and Zn than shoots while leaves usually acquire the highest concentrations of Pb. Cd concentrations among different plant organs are comparable except in M. spicatum where the highest Cd concentrations were recorded in the leaves. Our results also demonstrated that all the studied species can accumulate more than 1,450-fold the concentration of the investigated heavy elements in water rendering them of interest for use in phytoremediation studies of polluted waters. Given the absence of systematic water quality monitoring, heavy elements in plants, rather than sediments, provide a cost-effective means for assessing heavy element accumulation in aquatic systems during plant organ lifespan.

The Use of Water Plants in Biomonitoring And Phytoremediation of Waters Polluted with Heavy Metals

“…On the basis of the obtained results, it was confirmed that in comparison with sprouts, the roots of all studied plant types contain greater concentration of Cu and Zn, whereas the leaves contain the largest concentrations of Pb. Cd concentrations in different plant organs are comparable, except for M. spicatum, in which the largest Cd concentrations were observed in leaves [66].…”

“…Numerous bioindicators and biomonitors, among others algae [62,63], water animals [64,65] and macrophytes [54,66] are used to assess pollution of water environment. The main objectives of biomonitoring research of surface waters are the assessment of reservoirs pollution, identifying sources of pollution, long-term monitoring in order to define the dynamics of the changes, defining consequences of pollution for biocenosis and comparative studies between different elements of the ecosystem.…”

Heavy metal accumulation in the leaves, stem and root of the invasive submerged macrophyte Myriophyllum spicatum L. (Haloragaceae): an example of Kadin Creek (Mugla, Turkey)

“…The use of macrophyte as biological indicator in monitoring the heavy metals has some advantages as they tolerate high concentrations of the heavy metals in the water their samplings are easy and individuals are big (Zhou et al 2008). Due to their role as biological indicators for heavy metals and their capacity in refining the water from the contaminants, aquatic macrophytes have recently been a focus (Duman et al 2009;Kara 2010;Fawzy et al 2011). In this study, the bioaccumulation of heavy metals such as Cr, As, Cd, Hg and Pb in the roots, stem and leaves of Myriophyllum spicatum which were collected from the Kadın Creek in seasonal periods were analyzed.…”

Metal Uptake in Reeds from ‘Flowback’ Fluids

“…Most of some other trace metals (e.g., Ag, Co, Be, Pd) were also accumulated in belowground organs rather than aboveground tissues of reeds [19]. However, Fawazy et al [20] indicated that most Cu was stored in the roots while higher levels of Pb were found in the leaves of reeds. Similarly, according to the studies of Rzymski et al [21], majorities of metals (e.g., Fe, Mn, Zn, Cr) were found in the roots, but higher concentrations of Cd and Pb were found in the leaves of reeds [21].…”